Marchini joined the College of Dentistry in 2013. Before coming to Iowa, Marchini taught for 14 years as an assistant professor at Brazilian Universities for both undergraduate and graduate students. He taught prosthodontics, geriatric dentistry, and occlusion. Marchini also practiced dentistry in his private dental office located in Sao Jose dos Campos-Brazil.

At the University of Iowa College of Dentistry and Dental Clinics,Marchini teaches pre-doctoral students in the geriatrics and special needs program and treats patients in the faculty general practice.

Marchini acts as a general practitioner since graduating in 1996 with an emphasis in prosthodontics and geriatric dentistry.

Marchini's current research focus includes geriatric dental and general health epidemiology, and satisfaction of prosthodontic patients. Marchini is also interested on researching about the best way to teach dentistry, with particular interest to geriatric dentistry teaching.